1. Field of the Invention
The invention relates to a keyswitch, and especially relates to an illuminated keyswitch with backlight.
2. Description of the Prior Art
There is a kind of illuminated keyswitches using a light source (which may be spot light or surface light) disposed below the keycap for producing backlight to the keycap. The backlight can be observed by a user outside the keyswitch through the periphery or a light-penetrable portion of the keycap, which results in an illumination effect (e.g. by which the user can know the position of the key) or an indication effect (e.g. by which the user can know the name of the key). In general, the light source (e.g. an LED component) is usually disposed on the base, so if there are other components (e.g. mechanism for moving the keycap up and down relative to the base) disposed between the keycap and the base, the light emitted by the light source toward the keycap will be interfered. In principle, only the portion (i.e. the light-penetrable portion) of the keycap right above the light source can be illuminated uniformly by the light and is usually located at the periphery of the keycap, usually at a side portion of the periphery. On the whole, only a specific portion of the keycap can receive sufficient and uniform light, which limits the structural design of the light-penetrable portion of the keycap (including the size and location thereof). Furthermore, when the keycap is replaced with a new one, the light-penetrable portion of the new keycap still needs to align with the light source so that the light-penetrable portion can be illuminated uniformly by the light from the light source. Therefore, in the structural configuration of the illuminated keyswitches, the light source provides illumination light only in a single direction so the keycap as a whole cannot be illuminated uniformly by the illumination light, which further limits the design of the light-penetrable portion of the keycap.